Cerebellum Flashcards
what is the cerebellum concerned with?
the coordination of all somatic motor activity and the regulation of muscle tone and mechanisms that influence and maintain equilibrium
what are the four pairs of nuclei found within the cerebellum?
fastigial nucleus, globose nucleus, emboliform nucleus, and dentate nucleus
where do most efferents in the superior cerebellar peduncle originate at?
in the dentate nucleus
what is the dentate nucleus mostly responsible for?
for planning and execution of fine movement
what nucleus of the thalamus does the dentate nucleus of the cerebellum project its fibers to?
the ventral lateral nucleus of the thalamus
what is a critical link between the extrapyramidal system and the cerebellum?
the central tegmental fasciculus
what are the motor nuclei of the thalamus?
the ventral anterior nuclei and the ventral lateral nuclei
all information entering the cerebellar cortex eventually converges upon what?
the purkinje cells
what effect do the climbing fibers have on the purkinje cells?
a powerful excitatory effect
unilateral lesions of the cerebellum usually result in what type of deficits?
ipsilateral
what are the four common signs/symptoms of cerebellar lesions?
dysmetria, ataxia, dysdiadochokinesia, intention tremor
what does korsakoff’s syndrome present as?
the patient just making things up–> memory impairment
olivocerebellar fibers have a strong influence on what?
purkinje cells
unconscious precise proprioceptive information from the upper extremity is conveyed by what?
cuneocerebllar tract
the efferent fibers in the superior cerebllear peduncle project to where?
the ventral anterior nucleus
the cerebral cortex influences the cerebellum via what?
corticopontine fibers
the efferents of the dentate nucleus project to where?
the red nucleus and the ventral lateral nucleus of the thalamus
What are 4 of the inferior cerebellar peduncles?
dorsal spinocerebellar tract (DSCT), cuneocerebellar tract, trigeminocerebellar tract, olivocerebellar fibers
what does the dorsal spinal cerebellar tract convey?
unconscious precise proprioceptive information from the lower 1/2 of the body and lower extremities to the cerebellum
what does the cuneocerebellar tract convey?
unconscious precise proprioceptive information from the upper 1/2 of the body and the upper extremities
what does the trigeminocerebellar tract of the inferior cerebellar peduncle convey?
general proprioceptive and exteroceptive information from the head
where do the olivocerebellar fibers originate?
in the inferior olivary nucleus
what do the olivocerebellar fibers terminate as?
climbing fibers in the contralateral cerebellar hemisphere
the inferior olivary nucleus is an important processing and relay center for what?
sensory information from the spinal cord and the motor information from the reticular formation and extrapyramidal system
what does the inferior olivary nucleus (ION) receive direct input from?
the central tegmental fasciculus and the spino-olivary tract
where does the central tegmental fasciculus originate?
in the red nucleus, central periaqueductal gray and the midbrain tegmentum
what is significant about the central tegmental fasciculus?
it is a critical link between the extrapyramidal system and the cerebellum
what forms all of the middle cerebellar peduncle?
pontocerebellar fibers
what do the pontocerebellar fibers form?
part of an important feedback loop between the motor cortex and the cerebellum
what are the two tracts that make up the superior cerebellar peduncle?
the ventral spinocerebellar tract and the trigeminocerebellar tract
what does the ventral spinocerebellar tract convey?
unconscious general proprioceptive information from lumbosacral levels
what does the trigeminocerebellar tract of the superior cerebellar peduncle convey?
unconscious precise tactile and proprioceptive information from the head to the cerebellum
where do the fastigial and medial portion of the globose send their efferent fibers?
they send their fastigiobulbar fibers to the vestibular nuclei and RF
where do the lateral globose, emboliform, and dentate nuclei project their efferent fibers through?
the superior cerebellar peduncle
where do the efferent fibers from the dentate, lateral globose, and emboliform decussate?
in the upper pons and lower midbrain
chronic indigestion of ethanol may cause what?
a cortical atrophy of the anterior lobe of the cerebellum
